A motherboard, also known as the main board or system board is the main printed circuit board (PCB) found in computers and other expandable systems. It holds many of the electronic components of the system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals. Unlike a backplane, a motherboard includes significant sub-system electronics such as the processor and other components. In addition to the CPU and memory, the motherboard refers to a PCB with expansion capability which often includes sound cards, video cards, network cards, hard drives, or other forms of persistent storage, TV tuner cards, cards providing extra USB or FireWire slots and a variety of other custom components. To provide expansion capability for such cards, one or more expansion buses having expansion connectors are provided with the motherboard. For many users however, more functionality is often needed from the motherboard expansion buses than provided from the base offerings of the motherboard manufacturer.